Side effects of levomethadone and racemic methadone in a maintenance program

Sixty-six patients participated in a double-blind, crossover study comparing side effects, drug use, clinic attendance, and dose changes on levomethadone and d,l (racemic) methadone. The hypothesis under examination was that dextromethadone, while adding no narcotic actions to the racemate, was contributing to side effects. An earlier single-blind pilot study showed that 9 out of 11 side effects improved while patients were receiving levomethadone, but this larger study did not duplicate those results. Analysis of 25 variables showed no significant between levo- and racemic methadone. There appears to be no advantage in levomethadone over racemic methadone in the treatment of patients in maintenance programs.